Toner fixer with liquid-carrying porous material

Abstract

A toner fixing system has a heating member rotatable around an axis. The heating member includes a liquid-blocking barrier and a backing layer that define a liquid cavity not including the axis. The liquid cavity contains a heating liquid warmed above a glass transition temperature of the toner. A media-transport system transports the receiver medium along a transport path in which the receiver medium contacts or is entrained around the liquid-blocking barrier. Heat is transferred through the liquid-blocking barrier from the warmed heating liquid to the toner, raising a temperature of the toner to a level above the toner glass transition temperature.

The invention claimed is: 
     
       1. A toner fixing system for fixing toner onto a receiver medium, the toner having a toner glass transition temperature, comprising:
 a reservoir containing a heating liquid; 
 a liquid-heating system for warming the heating liquid in the reservoir to a temperature greater than the toner glass transition temperature; 
 a rotatable liquid-blocking barrier with an inner surface and an outer surface; 
 a media-transport system for transporting the receiver medium along a transport path in which the receiver medium contacts or is entrained around the liquid-blocking barrier in a contact zone so that the receiver medium is brought into contact with the outer surface of the liquid blocking barrier; and 
 a porous material arranged to absorb heating liquid from the reservoir and bring the absorbed heating liquid into contact with the inner surface of the liquid blocking layer for at least a portion of the contact zone, such that heat is transferred through the liquid-blocking barrier from the absorbed warmed heating liquid to the toner, thereby raising a temperature of the toner to a level above the toner glass transition temperature. 
 
     
     
       2. The toner fixing system of  claim 1  wherein the warmed heating liquid undergoes a phase change while heat is being transferred from the warmed heating liquid to the toner, and wherein the phase change releases heat such that at least a portion of the released heat contributes to raising the temperature of the toner. 
     
     
       3. The toner fixing system of  claim 2  wherein the phase change is a liquid-to-solid phase change, or another phase change that releases heat. 
     
     
       4. The toner fixing system of  claim 1  wherein the temperature of the warmed heating liquid is less than a medium degradation temperature above which the receiver medium irreversibly degrades. 
     
     
       5. The toner fixing system of  claim 1  wherein the temperature of the warmed heating liquid is less than a toner degradation temperature above which the toner irreversibly degrades. 
     
     
       6. The toner fixing system of  claim 1  wherein the porous material is permanently affixed to the inner surface of the liquid-blocking barrier. 
     
     
       7. The toner fixing system of  claim 6  wherein the rotatable liquid-blocking barrier is a circumferential surface of a drum which rotates around a central axis. 
     
     
       8. The toner fixing system of  claim 7  wherein the contact zone corresponds to an upper portion of the drum and a lower portion of the drum is submerged in the heating liquid in the reservoir where the porous material absorbs heating liquid, and wherein the drum rotates to transport the absorbed heating liquid up to the contact zone. 
     
     
       9. The toner fixing system of  claim 6  wherein the rotatable liquid-blocking barrier is a belt that is transported around a belt path. 
     
     
       10. The toner fixing system of  claim 9  wherein the belt is submerged in the heating liquid in the reservoir for a portion of the belt path where the porous material absorbs heating liquid, and wherein the belt moves around the belt path to transport the absorbed heating liquid to the contact zone. 
     
     
       11. The toner fixing system of  claim 1  wherein the porous material forms a porous belt that is transported around a porous belt path, and wherein the porous belt is brought into contact with the inner surface of the liquid-blocking barrier for a first portion of the porous belt path corresponding to at least a portion of the contact zone. 
     
     
       12. The toner fixing system of  claim 11  wherein the porous belt is transported through the reservoir containing the heating liquid during a second portion of the porous belt path where the porous material absorbs the warmed heating liquid.